Re: [PATCH 2/3] slub, hotplug: ignore unrelated node's hot-adding and hot-removing

[KOSAKI Motohiro <kosaki.motohiro@gmail.com>]

(9/27/12 2:47 AM), Lai Jiangshan wrote:
> SLUB only fucus on the nodes which has normal memory, so ignore the other
> node's hot-adding and hot-removing.
> 
> Aka: if some memroy of a node(which has no onlined memory) is online,
> but this new memory onlined is not normal memory(HIGH memory example),
> we should not allocate kmem_cache_node for SLUB.
> 
> And if the last normal memory is offlined, but the node still has memroy,
> we should remove kmem_cache_node for that node.(current code delay it when
> all of the memory is offlined)
> 
> so we only do something when marg->status_change_nid_normal > 0.
> marg->status_change_nid is not suitable here.
> 
> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
> ---
>  mm/slub.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/slub.c b/mm/slub.c
> index 2fdd96f..2d78639 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -3577,7 +3577,7 @@ static void slab_mem_offline_callback(void *arg)
>  	struct memory_notify *marg = arg;
>  	int offline_node;
>  
> -	offline_node = marg->status_change_nid;
> +	offline_node = marg->status_change_nid_normal;
>  
>  	/*
>  	 * If the node still has available memory. we need kmem_cache_node
> @@ -3610,7 +3610,7 @@ static int slab_mem_going_online_callback(void *arg)
>  	struct kmem_cache_node *n;
>  	struct kmem_cache *s;
>  	struct memory_notify *marg = arg;
> -	int nid = marg->status_change_nid;
> +	int nid = marg->status_change_nid_normal;
>  	int ret = 0;

Looks reasonable. I think slab need similar fix too.